1. Field of the Invention
The present invention relates to a light-emitting device using a light-emitting element which can provide fluorescence or phosphorescence when an electric field is applied to the element in which a film including an organic compound (hereinafter also referred to as a layer including an organic compound) is provided between a pair of electrodes, and a manufacturing method thereof.
Note that the “light-emitting device” includes image display devices, light-emitting devices, and light sources (including illumination devices). In addition, a module in which a connector, for example, an FPC (Flexible Printed Circuit), TAB (Tape Automated Bonding) tape, or a TCP (Tape Carrier Package), is attached to a light-emitting device; a module in which a printed circuit board is provided ahead of a TAB tape or a TCP; and a module in which an integrated circuit (IC) is directly mounted on a light-emitting device by a COG (Chip On Glass) method are all included in the “light-emitting device”. The present invention relates to a manufacturing method of a light-emitting device.
2. Description of the Related Art
In recent years, a light-emitting device having an EL element as a self-luminous light-emitting element has been actively developed. This light-emitting device is also called an organic EL display or an organic light-emitting diode. Such a light-emitting device has advantages in high response speed, low-voltage, low-power-consumption drive, and the like, which are suitable for displaying moving images; therefore, the light-emitting device has attracted attention as a next-generation display such as a new-generation mobile phone or portable information terminal (PDA).
An organic EL panel having an organic EL element is self-luminous type unlike a liquid crystal display device which needs a backlight, thus it is superior in visibility because high contrast can be easily realized and the viewing angle is wide. That is, the organic EL panel is more suitable for a display for outdoor use than a liquid crystal display, and a wide variety of applications thereof such as a display device of a mobile phone or a digital camera, or the like have been proposed.
In addition, an organic EL element means a light-emitting element including at least a cathode, an EL layer (a layer including an organic compound), and an anode, There are two types of the organic EL elements: a type where an EL layer is formed between two types of striped electrodes that are provided crosswise (passive matrix method); and a type where an EL layer is formed between a pixel electrode that is connected to a TFT and arranged in matrix, and an opposed electrode (active matrix method).
Further, an EL layer (a layer including an organic compound) has a stacked-layer structure typified by a stacked-layer structure of a hole-transporting layer, a light-emitting layer, and an electron-transporting layer. Further, EL materials for forming EL layers are roughly classified into low molecular (monomer) materials and high molecular (polymer) materials. As a film-formation method thereof, there are an evaporation method (including a vacuum evaporation method), a spin coating method, an inkjet method, a dipping method, an electropolymerization method, and the like.
For a full-color flat panel display, demands for high definition, high aperture ratio and high reliability have been increasing. Such demands are major issues in improving high definition (increase in the number of pixels) and miniaturization of a pixel pitch along with downsize of a light-emitting device. At the same time, there are increasing demands for increase of productivity and cost reduction.
When considering the manufacture of a full-color flat panel display using organic EL elements which emit red, green and blue respectively, high precision positional alignment for deposition is not provided by any deposition method, and thus the interval between pixels which emit different colors from each other is designed to be wide.
As a selective deposition method, Reference 1 discloses a manufacturing method of an organic light-emitting element which employs a donor film for an organic thin film and laser light (Reference 1: Japanese Published Patent Application No. H 10-208881).